1. Field Of The Invention
The present invention relates to curable coating compositions which when cured are substantially transparent and exhibit resistance to markings such as graffiti and scuffing and particulate buildup. In particular, the compositions of the present invention when cured provide protective coatings to surfaces to prevent absorption and/or wetting of ink compositions. The invention composition may also be used as mold release agents.
2. Brief Description Of Related Technology
Graffiti is understood to mean any unwanted markings on a surface, such as a building structure. Typically, it refers to unwanted paintings, words, and drawings. Such markings usually are applied by paints, such as spray paint, magic markers, or other inks. Paints are the most common source of graffiti, especially oil-based paints, such as enamels, epoxies, lacquers, and urethanes. Unwanted markings, however, may be produced by a variety of other sources, such as grease, crayons, and lipstick, among others.
Graffiti continues to be a problem of significant concern in today's society. Rather than a form of art, graffiti is considered vandalism and is an irritating eyesore in both public and private places. Graffiti. decreases the value of private properties and drives customers away from businesses. It often defaces public buildings and institutions, such as schools, trains and buses, as well as their stations, public restrooms, park structures, bridges, and tunnels, among many others.
A number of conventional cleaning techniques have been utilized to deal with the graffiti problem. These techniques typically involve cleaning the surface after it has been defaced by graffiti. Such cleaning techniques include sandblasting, sanding, high pressure power washing, and chemical treatments, among other similar procedures. Examples of cleaning compositions developed for removing graffiti are disclosed in U.S. Pat. No. 5,024,780 (Leys).
These cleaning methods, however, are costly and time-consuming. The cleaned or treated surface often is deteriorated by the harsh cleansing or chemicals. As a result, the surface has to be restored and repainted at high costs. Moreover, chemical treatment procedures often involve harsh, environmentally harmful chemicals, which pose dangers to human contact.
As such, it is desirable to develop compositions that protect surfaces from unwanted markings, which may be applied before any graffiti is created thereon. Protective coating compositions that have been developed in the past include those that are applied as part of the surface paint. These paint coatings, however, suffer the problem of damage by graffiti removal agents. Other protective coatings that have been developed include compositions that are applied on top of the paint or directly onto the surface. Examples of such coating compositions are disclosed in U.S. Pat. Nos. 5,387,434 (Black) and 5,773,091 (Perlman).
The protective coatings disclosed in Black include water-based wax containing compositions, sodium silicate, rosins, gums, and/or combinations thereof. Power washing can be used to remove these coatings with the graffiti from the surface. Perlman discloses protective coatings that are improved wax-based compositions. Perlman also discloses methods for cleaning the improved wax-based coatings, such as heating, pressurized water cleaning, and organic solvent based cleaning.
The present invention addresses the need for a mark resistant composition which cures at ambient conditions on a wide range of surfaces to provide a film coating on which among other things ink compositions are unable to penetrate or form a continuous film and hence are easily wiped off. In addition, the present invention provides such a composition that reduces the tendency of particulate buildup on surfaces coated therewith.